Electronic components such as semiconductor chips are becoming progressively smaller, while at the same time heat dissipation requirements thereof are increasing. Commonly, a thermal interface material (hereinafter, TIM) is utilized between the electronic component and a heat sink in order to fill air spaces therebetween thereby promoting efficient heat transfer.
Conventional TIMs are based on thermosetting or thermoplastic polymeric matrices. Nevertheless, the thermal conductivity of conformable polymers is rather low, typically in the range of 0.15 to 0.30 W/mK. To increase the thermal conductivity of the TIMs, thermally conductive particles are generally filled into the polymeric matrices. The thermal conductivity of these filled TIMs depends on various factors, such as, for example, the thermal conductivity of the particles and the packing of the particles in the polymeric matrix including content, density distribution, size and size distribution of the particles.
Generally, the TIM with high content of the particles has a relative high thermal conductivity. However, the higher the content of the particles filled in the TIM, the higher the viscosity of the matrix. Such high viscosity has a disadvantageous influence to the manufacturing processes to obtain desired TIMs, for example, a milling process. Further, the fluidity of these matrices would be relatively decreased due to the high viscosity thereby effacing the effectiveness of the TIM.
At present, a typical method for manufacturing the filled TIM includes a mixing process, i.e., admixing the particles into the matrix. The mixing process is generally performed in a mixing machine by continuously stilling of an agitator to disperse the particles into the matrix. Nevertheless, this stirring cannot bring out a satisfying mixing effect to the particles and the matrix, especially to heavy loading particles. For example, the particles are prone to agglomeration and cannot dispersedly and uniformly admix with the matrix. This would result in an enhanced inner thermal resistance thereby increasing an entire thermal resistance of the TIM. Thus, this mixing method is unsuitable for the manufacturing of the filled TIM.
What is needed, therefore, is a mixing method for manufacturing a TIM that is able to uniformly admix a plurality of particles and a matrix material.
What is also needed, therefore, is a mixing system for manufacturing a TIM.